page_title: Nonlinear theory of semiconductor lasers
section_title: Necessary condition for induced radiation of the 2nd kind
hierarchical_section_title: Nonlinear theory of semiconductor lasers / Gain in a semiconductor laser / Necessary condition for induced radiation of the 2nd kind
caption_attribution_description: Functions g1(I) and g2(I) versus energy flux I for two sets of characteristic parameters
context_page_description: Laser theory of Fabry-Perot semiconductor lasers proves to be nonlinear, since the gain, the refractive index and the loss coefficient are the functions of energy flux. The nonlinear theory made it possible to explain a number of experiments some of which could not even be explained, much less modeled, on the basis of other theoretical models; this suggests that the nonlinear theory developed is a new paradigm of the laser theory.
context_section_description: The necessary condition of induced radiation of the 2nd kind formulated by Noppe is that:
  The necessary condition of induced radiation of the 2nd kind allows formulating the basic restriction of laser capacity, which has been confirmed experimentally:
  where I is energy flux; I(M) is the characteristic parameter of ultimate power. Figure 1 shows the function g(I) for two sets of characteristic parameters.
caption: Figure.1. Functions 
    
      
        
          
            g
            
              1
            
          
          (
          I
          )
        
      
      {\displaystyle g_{1}(I)}
    
   and 
    
      
        
          
            g
            
              2
            
          
          (
          I
          )
        
      
      {\displaystyle g_{2}(I)}
    
   versus energy flux I for two sets of characteristic parameters.[1][2]
exif: {}